DESCRIPTION

TITLE: Process for colouring keratin materials using a particular oily dispersion and at least two amine compounds that are different from each other

The present invention relates to a cosmetic process for treating keratin materials, in particular human keratin materials such as the hair, the skin or the lips, comprising the application to said keratin materials of a particular oily dispersion, of a composition comprising at least two amine compounds that are different from each other and of at least one dyestuff.

The present invention also relates to a device containing at least two compartments containing a particular oily dispersion, a composition comprising at least two amine compounds that are different from each other and at least one dyestuff.

Many people have for a long time sought to modify the colour of their hair or to make up their skin and/or lips in order, for example, to hide their grey hair or skin marks or to improve/enhance their natural tone.

Two types of dyeing have essentially been developed as regards keratin fibres, and notably the hair.

The first type of dyeing is “permanent” or oxidation dyeing, which uses dye compositions containing oxidation dye precursors, generally known as oxidation bases. These oxidation bases are colourless or weakly coloured compounds which, when combined with oxidizing products, may give rise to coloured compounds via a process of oxidative condensation.

It is also known that the shades obtained with these oxidation bases may be varied by combining them with couplers or colour modifiers. The variety of molecules used as oxidation bases and couplers allows a wide range of colours to be obtained.

The second type of dyeing is “semi-permanent” dyeing or direct dyeing, which consists in applying, to the keratin fibres, direct dyes, which are coloured and colouring molecules that have affinity for said fibres, in leaving them on for a time, and then in rinsing them off.

This type of process does not require the use of an oxidizing agent to develop the colouring. However, it is possible to use such an agent in order to obtain, along with the colouring, a lightening effect. This is then referred to as direct dyeing or semi permanent dyeing under lightening conditions.

These conventional dyeing processes can damage the integrity of keratin fibres. Milder solutions, which are also known as makeup solutions and are based on weak physicochemical interactions, make it possible to deposit colouring and/or nacreous agents at the surface without threatening the fibre integrity. Among the colouring agents that may be used in these makeup compositions, pigments and in particular nacres, such as nacres of mica/iron oxide type, have advantageous colouring properties.

These colouring agents and/or nacreous agents are notably used in cosmetic products that may be applied to the skin and/or the lips, for instance makeup products such as lipsticks or foundations.

However, the colourings thus obtained on the hair or the skin and/or the lips are only short-lasting. Specifically, given the low interaction between the colouring agents and the keratin materials, the colourings have a tendency to fade out, or even to disappear, rapidly, with respect to external agents (brushing, friction, food, etc.), such as light, sweat and mechanical actions, and notably after a few shampoo washes.

Added to these drawbacks are also the risks of transfer of these colourings onto the users' hands and/or clothing or any other support during the application and/or use of these compositions on the keratin materials.

Thus, there is a real need to develop a cosmetic treatment process, in particular for colouring or making up keratin materials, and notably human keratin materials such as the hair, the lips or the skin, which affords colouring properties and also good cosmetic properties to said keratin materials, notably in terms of sheen, softness and comfort. This process must also give a non-tacky feel and a volume effect, while at the same time protecting the integrity of the keratin materials.

The coating thus obtained must be persistent with respect to shampoo washing and to the various attacking factors to which said keratin materials may be subjected, such as brushing and/or friction for a hair application. This coating must also be resistant to attacking factors such as water, olive oil or sebum for applications to the lips or the skin.

It has been discovered, surprisingly, that a process in at least two steps, comprising the application to keratin materials of a particular oily dispersion followed by the application of a composition comprising at least two amine compounds that are different from each other in the presence of at least one dyestuff makes it possible to achieve the above objectives, notably to give a coloured coating which has good cosmetic properties, notably in terms of sheen, comfort and volume, which are capable of persisting over time and of being resistant to the various external attacking factors. Thus, one subject of the present invention is notably a cosmetic process for treating keratin materials, in particular human keratin materials such as the hair, the lips or the skin, comprising:

(i) a step of applying to said keratin materials an oily dispersion (A), which is preferably anhydrous, comprising:

(1) one or more particles including one or more ethylenic polymers chosen from: a) (Ci-C ₄ )alkyl (Ci-C ₄ )(alkyl)acrylate ethylenic homopolymers, b) ethylenic copolymers of bl) (Ci-C ₄ )alkyl (Ci-C ₄ )(alkyl)acrylate and of b2) ethylenic monomers comprising one or more carboxyl, anhydride, phosphoric acid, sulfonic acid and/or aryl groups, and c) (Ci-C ₄ )alkyl (Ci-C ₄ )(alkyl)acrylate ethylenic copolymers;

(2) one or more stabilizers, other than said ethylenic polymer(s) (1), chosen from: d) (C ₉ -C ₂₂ )alkyl (Ci-C ₆ )(alkyl)acrylate ethylenic homopolymers, and e) ethylenic copolymers of (C ₉ -C ₂₂ )alkyl (Ci-C ₆ )(alkyl)acrylate and of (Ci-C ₄ )alkyl (Ci-C ₄ )(alkyl)acrylate, and

(3) one or more hydrocarbon-based oils, followed by

(ii) a step of applying to said keratin materials a composition (B) comprising:

(4) one or more amino silicones, and

(5) one or more salified or non-salified polysaccharides bearing amine group(s); it being understood that said process involves (6) one or more dyestuffs chosen from colorants, pigments and mixtures thereof, said dyestuff(s) being present in the oily dispersion (A) and/or in composition (B) and/or in another composition (C).

The at least two-step process of the present invention makes it possible to obtain a good coloured coating which has improved cosmetic properties. Specifically, the colourings thus obtained are bright and gentle.

The colourings are also resistant to sebum, to water and to friction and all other mechanical attacking factors such as brushing or contact with food. Moreover, the keratin materials treated by means of the process of the invention do not transfer colour onto fabrics and do not stain the hands or the scalp.

The present invention also relates to a multi-compartment device comprising: - a first compartment containing an oily dispersion (A) as defined previously,

- a second compartment containing a composition (B) as defined previously, and

- optionally a third compartment containing one or more dyestuffs chosen from colorants, pigments and mixtures thereof.

Other subjects, characteristics, aspects and advantages of the invention will emerge even more clearly on reading the description and the examples that follow.

For the purposes of the present invention and unless otherwise indicated:

- an “ alkyl radical ” is a linear or branched saturated C ₁ -C ₆ , preferably C ₁ -C ₄ , hydrocarbon-based group such as methyl, ethyl, isopropyl and tert-butyl;

- a “f C ₉ -C ₂₂ )alkyr radical is a saturated, linear or branched C ₉ -C ₂₂ , in particular C ₁₀ -C ₂₀ , preferentially C ₁₂ -C ₁₈ , more preferentially C ₁₂ -C ₁₆ hydrocarbon- based group, such as stearyl, behenyl, isodecyl, lauryl, hexadecyl or myristyl;

- an “ alkylene radical ” is a linear or branched divalent saturated Ci-Cs, in particular C ₁ -C ₆ , preferably C ₁ -C ₄ hydrocarbon-based group such as methylene, ethylene or propylene; a “ cycloalkyl ” radical is a cyclic saturated hydrocarbon-based group comprising from 1 to 3 rings, preferably 2 rings, and comprising from 3 to 13 carbon atoms, preferably between 5 and 10 carbon atoms, such as cyclopentyl, cyclohexyl, cycloheptyl, norbomyl, or isobomyl, the cycloalkyl radical possibly being substituted with one or more (Ci-C ₄ )alkyl groups such as methyl; preferably, the cycloalkyl group is an isobornyl group. a “ cyclic ” radical is a cyclic saturated or unsaturated, aromatic or non aromatic hydrocarbon-based group comprising from 1 to 3 rings, preferably 1 ring, and comprising from 3 to 10 carbon atoms, such as cyclohexyl or phenyl;

- an “aryl” radical is a monocyclic or bicyclic, fused or non-fused, unsaturated cyclic aromatic radical comprising from 6 to 12 carbon atoms; preferably, the aryl group comprises 1 ring and contains 6 carbon atoms, such as phenyl; an “ aryloxy ” radical is an aryl-oxy, i.e. aryl-O-, radical, with aryl as defined previously, preferably phenoxy; an “ aryl(Ci-C ₄ )alkoxy ” radical is an aryl-(Ci-C ₄ )alkyl-0-, radical, preferably benzoxy;

- the term “ insoluble monomer” thus means any monomer whose homopolymer or copolymer is not in soluble form, i.e. not fully dissolved at a concentration of greater than 5% by weight at room temperature (20°C) in said medium. However, the “ insoluble ” monomers may, as monomers, be soluble or insoluble in the hydrocarbon-based oil(s) (3), it being understood that they become insoluble after polymerization the hydrocarbon-based oil(s) (3);

- the term “ ethylenic homopolymer” means a polymer derived from the polymerization of identical ethylenic monomers;

- the term “ ethylenic copolymer” means a polymer derived from the polymerization of monomers that are different from each other, in particular at least two monomers that are different from each other. Preferably, the ethylenic copolymer of the invention is derived from two or three monomers that are different from each other, more preferentially derived from two monomers that are different from each other;

- the term “ ethylenic monomer” means an organic compound including one or more conjugated or non-conjugated unsaturations of >C=C< type, which is capable of polymerizing;

- the term “ soluble monomer” means any monomer whose homopolymer or copolymer, preferably homopolymer, is soluble to at least 5% by weight, at 20°C, in the hydrocarbon-based oil(s) (3) of the dispersion. The homopolymer is fully dissolved in the hydrocarbon-based oil(s) (3), visually at 20°C, i.e. no insoluble deposit or precipitate or agglomerate or sediment is visually noted. However, the "soluble” monomers may, as monomers, be soluble or insoluble in the hydrocarbon-based oil(s) (3), it being understood that they become soluble after polymerization the hydrocarbon-based oil(s) (3);

- the term ‘ fatty substance” means an organic compound that is insoluble in water at ordinary room temperature (25 °C) and at atmospheric pressure (760 mmHg) (solubility of less than 5%, preferably 1% and even more preferentially 0.1%). They bear in their structure at least one hydrocarbon-based chain including at least 6 carbon atoms or a sequence of at least two siloxane groups. In addition, the fatty substances are generally soluble in organic solvents under the same temperature and pressure conditions, for instance chloroform, ethanol, benzene, liquid petroleum jelly or decamethylcyclopentasiloxane. These fatty substances are neither polyoxyethylenated nor polyglycerolated. They are different from fatty acids, since salified fatty acids constitute soaps that are generally soluble in aqueous media;

- the term “ liquid ” fatty substance notably refers to a fatty substance that is liquid at 25°C and 1 atmosphere; preferably, said fatty substance has a viscosity of less than or equal to 7000 centipoises at 20°C; - the term “ hydrocarbon-based ’ fatty substance means a fatty substance which comprises at least 50% by weight, notably from 50% to 100% by weight, for example from 60% to 99% by weight, or even from 65% to 95% by weight, or even from 70% to 90% by weight, relative to the total weight of said fatty substance, of carbon-based compound, which is liquid at 25°C, having a global solubility parameter in the Hansen solubility space of less than or equal to 20 (MPa) ¹⁷² , or a mixture of such compounds;

The global solubility parameter d in the Hansen solubility space is defined in the article “Solubility parameter values” by Grulke in the book Polymer Handbook , 3rd Edition, chapter VII, pages 519-559, by the relationship: d = ( d _D ² + dp ² + d _H ² ) ¹⁷² in which:

- do characterizes the London dispersion forces derived from the formation of dipoles induced during molecular impacts,

- d _p characterizes the Debye interaction forces between permanent dipoles,

- d _H characterizes the forces of specific interactions (such as hydrogen bonding, acid/base, donor/acceptor, etc.).

The definition of solvents in the Hansen three-dimensional solubility space is described in the article by Hansen: The three-dimensional solubility parameters, J. Paint Technol. 39, 105 (1967);

- the term “ anhydrous " dispersion or composition means a dispersion or composition containing less than 2% by weight of water, or even less than 0.5% by weight of water, and notably water-free; where appropriate, such small amounts of water may notably be introduced by ingredients of the composition that may contain residual amounts thereof;

- the limits of a range of values are included in that range, notably in the expressions "between... and ..." and "ranging from ... to ..."; Moreover, the expression "at least one" used in the present description is equivalent to the expression "one or more".

The oily dispersion (A)

The cosmetic treatment process according to the present invention comprises a step of applying to said keratin materials an oily dispersion (A) as defined previously.

The oily dispersion (A) of the invention comprises (1) one or more particles including at least one ethylenic polymer surface-stabilized with (2) at least one stabilizer in a medium which is preferably anhydrous, containing (3) at least one hydrocarbon-based oil.

In order to obtain such an oily dispersion (A), it is proposed to polymerize particular monomers that are capable of forming the polymeric core (1) of the particles in the presence of a polymeric statistical stabilizer (2); the particles comprising in major amount a portion (2) that is soluble and in minor amount a portion (1) that is insoluble in the dispersion medium, i.e. in the hydrocarbon-based oil(s) (3).

The dispersions according to the invention consist of particles, which are generally spherical, of at least one surface-stabilized polymer, in an anhydrous medium.

Preferably, said particles (1) are non-crosslinked or sparingly crosslinked.

The ethylenic polymer particles

The oily dispersion (A) used in the cosmetic treatment process according to the present invention comprises (1) one or more particles including one or more ethylenic polymers chosen from: a) ethylenic homopolymers of (Ci-C4)alkyl (Ci-C4)(alkyl)acrylate, preferably ethylenic homopolymers of (Ci-C4)alkyl (meth)acrylate, b) ethylenic copolymers of bl) (Ci-C4)alkyl (Ci-C4)(alkyl)acrylate and of b2) ethylenic monomers comprising one or more carboxyl, anhydride, phosphoric acid, sulfonic acid and/or aryl groups, preferably ethylenic copolymers of (Ci-C4)alkyl (meth)acrylate and of (meth)acrylic acid, and c) ethylenic copolymers of (Ci-C4)alkyl (Ci-C4)(alkyl)acrylate preferably ethylenic copolymers of (Ci-C4)alkyl (meth) acrylate.

In other words, the particle(s) consist of an ethylenic polymeric core derived from homopolymers a) or from copolymers b) or c) as defined previously.

According to a first embodiment of the invention, the ethylenic polymer(s) of the particles (1) are chosen from acrylate homopolymers a), resulting from the polymerization of identical monomers of formula (la):

H ₂ C=C(R)-C(0)-0-R' (la), in which formula (la)

- R represents a hydrogen atom or a linear or branched Ci to C _A alkyl group, such as methyl, and - R’ represents a linear or branched Ci to CA alkyl group, such as methyl or ethyl.

Preferably, the monomers of formula (la) are Ci to CA alkyl acrylates, such as methyl acrylate.

According to a second embodiment of the invention, the ethylenic polymer(s) of the particles (1) are chosen from acrylate copolymers b), resulting from the copolymerization :

- of at least one monomer of formula (la) as defined previously, preferably a Ci to CA alkyl (meth)acrylate, more preferentially a methyl (meth) acrylate or ethyl acrylate monomer, and

- of at least one monomer of formula (lb):

H ₂ C=C(R)-C(0)-0-H (lb) in which formula (lb) R is as defined previously for formula (la), preferably an acrylic acid monomer.

According to this embodiment, the amount of acrylic acid monomer(s) preferably ranges from 0.1% to 15% by weight, relative to the total weight of monomers of the particles (1), i.e. of monomers constituting the polymeric core of the particles (1).

According to this second embodiment, the ethylenic polymer is preferably an ethylenic copolymer obtained from the copolymerization of acrylic acid with one or more Ci to CA alkyl (meth)acrylate monomers.

According to a third embodiment of the invention, the ethylenic polymer(s) of the particles (1) are chosen from acrylate ethylenic copolymers c), resulting from the copolymerization:

- of at least two monomers, which are different from each other, of formula (la) as defined previously, preferably of at least two monomers, which are different from each other, of Ci to CA alkyl (meth)acrylate, such as methyl acrylate and ethyl acrylate, and

- optionally of at least one monomer of formula (lb) as defined previously.

Preferably, the ethylenic polymer(s) of the particles (1) are copolymers derived from the polymerization of at least one Ci to CA alkyl (meth) acrylate monomer. The Ci to CA alkyl (meth)acrylate monomer(s) are preferably chosen from methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth) acrylate and tert-butyl (meth)acrylate, and mixtures thereof, and more preferentially from methyl (meth)acrylate and ethyl (meth)acrylate, and mixtures thereof.

According to a first variant, the Ci to C ₄ alkyl (meth) acrylate monomer(s) are Ci to C ₄ alkyl acrylate monomers, more preferentially chosen from methyl acrylate, ethyl acrylate and mixtures thereof.

According to a second variant, the Ci to C ₄ alkyl (meth)acrylate monomer(s) are Ci to C ₄ alkyl methacrylate monomers, more preferentially chosen from methyl methacrylate, ethyl methacrylate and mixtures thereof, better still methyl methacrylate.

According to a fourth embodiment of the invention, the ethylenic polymer of the particles (1) is a copolymer resulting from the copolymerization bl) of at least one (Ci-C ₄ )alkyl (Ci-C ₄ )(alkyl)acrylate monomer, and b2) of at least one ethylenic monomer comprising one or more carboxyl, anhydride, phosphoric acid, sulfonic acid and/or aryl groups, such as benzyl.

More particularly, the ethylenic monomer(s) b2) comprising one or more carboxyl, anhydride, phosphoric acid, sulfonic acid and/or aryl groups are chosen from:

- the compounds of formula R ¹ (R ² )C=C(R ³ )-Acid with R ¹ , R ² and R ³ , which may be identical or different, representing a hydrogen atom or a CO ₂ H, H ₂ PO ₄ or SO ₃ H group, and Acid representing a carboxyl group, a phosphoric acid or a sulfonic acid, preferably a carboxyl group, it being understood that R ¹ , R ² and R ³ cannot simultaneously represent a hydrogen atom;

- the compounds of formula H2C=C(R)-C(0)-N(R')-Alk-Acid with R and R', which may be identical or different, representing a hydrogen atom or a linear or branched Ci to C ₄ alkyl group; Aik representing a (Ci-C ₆ )alkylene group optionally substituted with at least one group chosen from Acid as defined previously and hydroxyl; and Acid being as defined previously, preferably a carboxyl group or a sulfonic acid;

- the compounds of formula Ar-(R ^a )C=C(R ^b )-R ^c with R ^a , R ^b and R ^c , which may be identical or different, representing a hydrogen atom or a linear or branched Ci to C ₄ alkyl group, and Ar representing an aryl group, preferably benzyl, optionally substituted with at least one acid group CO ₂ H, H ₂ PO ₄ or SO ₃ H, preferably substituted with a CO ₂ H or SO ₃ H group;

- the maleic anhydrides of formulae (Ila) and (lib): in which formulae (Ila) and (lib) R _a , R _b and R _c , which may be identical or different, represent a hydrogen atom or a linear or branched Ci to C4 alkyl group; preferably, R _a , R _b , and R _c are identical and represent a hydrogen atom; and

- the compounds of formula H2C=C(R)-C(0)-0-H with R representing a hydrogen atom or a linear or branched Ci to C4 alkyl group, such as methyl.

Preferably, the ethylenic monomer(s) b2) are chosen from (Ci- C4)(alkyl)acrylic acids. Advantageously, the ethylenic polymer of the particles (1) is chosen from copolymers of a (Ci-C4)alkyl (meth) acrylate and of (meth)acrylic acid.

More preferentially, the ethylenic monomer(s) b2) are chosen from crotonic acid, maleic anhydride, itaconic acid, fumaric acid, maleic acid, styrenesulfonic acid, vinylbenzoic acid, vinylphosphoric acid, acrylic acid, methacrylic acid, acrylamidopropanesulfonic acid, acrylamidoglycolic acid, acrylic acid, salts thereof and mixtures thereof, and better still the ethylenic monomer b2) is acrylic acid.

Preferably, the ethylenic polymer(s) of the particles (1) are copolymers resulting from the copolymerization bl) of at least one Ci to C4 alkyl (meth)acrylate monomer, preferably chosen from methyl (meth)acrylate, ethyl (meth)acrylate and mixtures thereof and b2) of at least one ethylenic monomer chosen from the maleic anhydrides of formulae (Ila) and (lib) as defined above.

The polymer particles (1) of dispersion (A) preferably have a number- average size ranging from 5 to 500 nm, more preferentially from 10 to 400 nm and better still ranging from 20 to 300 nm.

The final size of the polymer particles (1) is preferably greater than 100 nm. In particular, they have a number-average size ranging from 100 nm to 500 nm, more particularly ranging from 150 nm to 400 nm and even more particularly ranging from 160 nm to 300 nm.

The average size of the particles (1) is determined via conventional methods known to those skilled in the art. Mention may be made, for example, of the particle size method which may be performed using a Malvern NanoZS machine. The method employed may be dynamic light scattering (DLS), also known as quasi-elastic light scattering (QELS), individual particle tracking analysis (Nanoparticle Tracking Analysis, NTA), laser scattering (LS), nanometre-sized to millimetre-sized particle size distributions, and spatial filter velocimetry.

The sample is pipetted into a disposable plastic tank (four transparent faces, side length of 1 cm and volume of 4 mL) placed in the measuring cell. The sample is analysed on the basis of a cumulant fit method which leads to a monomodal particle size distribution characterized by an intensity-weighted mean diameter d (nm) and a size polydispersity factor Q.

Preferably, the monomers that are capable of forming the polymeric core of the particle i) are chosen from monomers that are insoluble in the hydrocarbon-based oil(s) (3) of the oily dispersion (A). The insoluble monomers preferably represent 100% by weight relative to the total weight of the monomers forming the polymeric core of the particle.

The total content of said ethylenic polymer particle(s) (1) present in the oily dispersion (A) preferably ranges from 20% to 50% by weight and more preferentially from 25% to 50% by weight relative to the total weight of the oily dispersion (A).

The stabilizers

The oily dispersion (A) used in the cosmetic treatment process according to the present invention also comprises one or more stabilizers (2), different from said ethylenic polymer(s) (1) defined above, chosen from: d) (C9-C22)alkyl (Ci-C ₆ )(alkyl)acrylate ethylenic homopolymers, and e) ethylenic copolymers of (C9-C22)alkyl (Ci-C ₆ )(alkyl)acrylate and of (Ci- C4)alkyl (Ci-C4)(alkyl)acrylate.

Preferably, only one type of stabilizer (2) is used in the process of the invention.

According to a first embodiment of the invention, the stabilizer(s) (2) are chosen from d) ethylenic (C9-C22)alkyl (Ci-C ₆ )(alkyl)acrylate homopolymers, in particular from ethylenic (Cg-Cis)alkyl (Ci-C4)(alkyl)acrylate homopolymers, preferably from ethylenic (C9-C22)alkyl (meth)acrylate homopolymers and more preferentially from ethylenic (Cg-Cis)alkyl (meth)acrylate homopolymers.

More particularly, the stabilizer(s) (2) are chosen from d) ethylenic homopolymers obtained from the polymerization of monomers of formula H2C=C(R)- C(0)-0-R” with R representing a hydrogen atom or a linear or branched Ci to Ce and preferably Ci to C ₄ alkyl group, such as methyl, and R" representing a linear or branched C ₉ to C ₂₂ and preferably C ₉ to Cis alkyl group. Preferably, R" represents an isodecyl, lauryl, stearyl, hexadecyl or behenyl group.

According to a second embodiment of the invention, the stabilizer(s) (2) are chosen from e) ethylenic copolymers of (C ₉ -C ₂₂ )alkyl (Ci-C ₆ )(alkyl)acrylate and of (Ci-C ₄ )alkyl (Ci-C ₄ )(alkyl)acrylate, preferably from copolymers of (Cg-Cis)alkyl (Ci- C ₄ )(alkyl)acrylate and of (Ci-C ₄ )alkyl (Ci-C ₄ )(alkyl)acrylate and more preferentially from copolymers of (Cg-Cis)alkyl (meth)acrylate and of (Ci-C ₄ )alkyl (meth)acrylate.

More preferentially, the stabilizer(s) (2) are chosen from the ethylenic copolymers e) of formulae (Ilia) and (Mb):

H ₂ C=C(R)-C(0)-0-R’ (Ilia) H ₂ C=C(R)-C(0)-0-R" (Mb) in which formulae (Ilia) and (Mb)

- R, which may be identical or different, represent a hydrogen atom or a linear or branched Ci to C ₄ alkyl group, such as methyl,

- R’ represents a linear or branched Ci to C ₄ alkyl group such as methyl or ethyl, and

- R” represents a linear or branched C ₉ to C ₂₂ and preferably C ₁₀ to C ₂₀ alkyl group, and in particular a (C _2n )alkyl group with n representing an integer equal to 5, 6, 7, 8, 9 or 10. Preferably, R" represents an isodecyl, lauryl, stearyl, hexadecyl or behenyl group.

Preferentially, the stabilizer(s) (2) are chosen from copolymers derived from the copolymerization of monomers chosen from isodecyl (meth)acrylates, lauryl (meth)acrylates, stearyl (meth)acrylates, hexadecyl (meth)acrylates, behenyl (meth)acrylates and Ci to C ₄ alkyl (meth)acrylates, preferably methyl (meth)acrylate.

More preferentially, the stabilizer(s) (2) are chosen from copolymers derived from the copolymerization of monomers chosen from isodecyl (meth)acrylates, lauryl (meth)acrylates, stearyl (meth)acrylates, hexadecyl (meth)acrylates and Ci to C ₄ alkyl (meth)acrylates, preferably methyl (meth) acrylate or ethyl (meth)acrylate.

More particularly, the stabilizer(s) (2) are chosen from isodecyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, hexadecyl (meth)acrylate or behenyl (meth) acrylate homopolymers, and statistical copolymers of isodecyl (meth)acrylate, of lauryl (meth)acrylate, of stearyl (meth)acrylate, of hexadecyl (meth)acrylate, of behenyl (meth)acrylate and of Ci to C ₄ alkyl (meth)acrylate, preferably present in a weight ratio of lauryl, stearyl, hexadecyl, behenyl (meth)acrylate/Ci-C4 alkyl (meth)acrylate of greater than 4.5.

Advantageously, said weight ratio ranges from 5 to 15 and more preferentially said weight ratio ranges from 5.5 to 12.

According to another embodiment, the stabilizer(s) (2) are chosen from the ethylenic copolymers e) derived from the copolymerization of at least one monomer of formula (Mb) as defined previously and of at least two monomers, which are different from each other, of formula (Ilia) as defined previously.

Preferentially, the stabilizer(s) (2) are chosen from copolymers obtained from the copolymerization:

- of at least one monomer chosen from isodecyl, lauryl, stearyl, hexadecyl or behenyl (meth)acrylates, and

- of at least two monomers, which are different from each other, of Ci to C4 alkyl (meth)acrylate, preferably of at least one methyl acrylate monomer and of at least one ethyl acrylate monomer. In particular, the weight ratio of isodecyl, lauryl, stearyl, hexadecyl, behenyl (meth)acrylates/Ci to C4 alkyl (meth)acrylate is greater than 4. Advantageously, said weight ratio ranges from 5 to 10 and more preferentially said weight ratio ranges from 5.5 to 7.

For these statistical copolymers, the defined weight ratio makes it possible to obtain a polymer dispersion that is stable, notably after storage for seven days at room temperature.

According to a particular embodiment of the invention, the oily dispersion (A) includes from 2% to 40% by weight, in particular from 4% to 25% by weight and notably from 5.5% to 20% by weight of (C9-C22)alkyl (Ci-C ₆ )(alkyl)acrylate monomers included in d) or e) that are soluble in the hydrocarbon-based oil(s) (3), relative to the total weight of soluble and insoluble polymers contained in said oily dispersion (A).

Advantageously, the weight ratio between the content of the stabilizer(s) (2), other than the ethylenic polymers of the particles (1), and the content of the ethylenic polymer particle(s) (1), present in the oily dispersion (A), ranges from 0.5 to 2, and this weight ratio is preferably equal to 1.

The total content of the stabilizer(s) (2), present in the oily dispersion (A) of the invention, preferably ranges from 2% to 40% by weight, more preferentially from 3% to 30% by weight, and better still from 4% to 25% by weight relative to the total weight of the oily dispersion (A). Preferably, the stabilizer(s) (2) and the particle(s) i) have a number-average molecular weight (Mn) of between 1000 and 1 000 000 g/mol, notably between 5000 and 500000 g/mol and better still between 10000 and 300000 g/mol.

The oily dispersion (A) according to the invention is finally formed from polymeric particles, of relatively large diameter, i.e. preferably greater than 100 nm, and leads to shiny film-forming deposits which are resistant to fatty substances at room temperature (25°C), and which are notably advantageous for makeup applications.

The hydrocarbon-based oils

The oily dispersion (A) used in the cosmetic treatment process according to the present invention also comprises (3) one or more hydrocarbon-based oils.

This oil may be volatile (vapour pressure greater than or equal to 0.13 Pa measured at 25°C) or non-volatile (vapour pressure less than 0.13 Pa measured at 25°C).

Preferably, the hydrocarbon-based oil is volatile.

The hydrocarbon-based oil is a hydrocarbon-based fatty substance that is liquid at room temperature (25 °C) and at atmospheric pressure.

The hydrocarbon-based oil is preferably chosen from:

- branched Cs- to C _\ e alkanes such as Cs to C½ isoalkanes of petroleum origin (also known as isoparaffins), for instance isododecane (also known as 2, 2, 4,4,6- pentamethylheptane), isodecane, isohexadecane and, for example, the oils sold under the trade name Isopar or Permethyl;

- linear Cs to Ci ₆ alkanes, for instance n-dodecane (C12) and n-tetradecane (C14) sold by Sasol under the references, respectively, Parafol 12-97 and Parafol 14- 97, and also mixtures thereof, the undecane-tridecane mixture, mixtures of n-undecane (C11) and of n-tridecane (C13) obtained in examples 1 and 2 of patent application WO 2008/155059 from the company Cognis, and mixtures thereof;

- short-chain esters (containing from 3 to 8 carbon atoms in total) such as ethyl acetate, methyl acetate, propyl acetate or n-butyl acetate;

- hydrocarbon-based oils of plant origin such as triglycerides consisting of fatty acid esters of glycerol, the fatty acids of which may have chain lengths ranging from Ce to C24, these chains possibly being linear or branched, and saturated or unsaturated; these oils are notably heptanoic acid or octanoic acid triglycerides, or alternatively wheatgerm oil, sunflower oil, grapeseed oil, sesame seed oil, com oil, apricot oil, castor oil, shea oil, avocado oil, olive oil, soybean oil, sweet almond oil, palm oil, rapeseed oil, cotton oil, hazelnut oil, macadamia oil, jojoba oil, alfalfa oil, poppy oil, pumpkin oil, marrow oil, blackcurrant oil, evening primrose oil, millet oil, barley oil, quinoa oil, rye oil, safflower oil, candlenut oil, passion flower oil or musk rose oil; shea butter; or else caprylic/capric acid triglycerides, for instance those sold by the company Stearinerie Dubois or those sold under the names Miglyol 810 ^® , 812 ^® and 818 ^® by the company Dynamit Nobel;

- synthetic ethers containing from 10 to 40 carbon atoms;

- linear or branched hydrocarbons of mineral or synthetic origin comprising more than 16 carbon atoms, such as petroleum jelly, polydecenes, hydrogenated polyisobutene such as Parleam ^® , squalane and liquid paraffins, and mixtures thereof;

- synthetic esters such as oils of formula R1COOR2 in which Ri represents a linear or branched fatty acid residue including from 1 to 40 carbon atoms and R2 represents a, notably branched, hydrocarbon-based chain containing from 1 to 40 carbon atoms, on condition that Ri + R2 > 10, for instance purcellin oil (cetostearyl octanoate), isopropyl myristate, isopropyl palmitate, C12 to C15 alkyl benzoates, hexyl laurate, diisopropyl adipate, isononyl isononanoate, 2-ethylhexyl palmitate, isostearyl isostearate, 2-hexyldecyl laurate, 2-octyldecyl palmitate, 2-octyldodecyl myristate, alcohol or polyalcohol heptanoates, octanoates, decanoates or ricinoleates such as propylene glycol dioctanoate; hydroxylated esters such as isostearyl lactate, diisostearyl malate and 2-octyldodecyl lactate; polyol esters and pentaerythritol esters;

- fatty alcohols that are liquid at room temperature, with a branched and/or unsaturated carbon-based chain containing from 12 to 26 carbon atoms, for instance octyldodecanol, isostearyl alcohol, oleyl alcohol, 2-hexyldecanol, 2-butyloctanol and 2-undecylpentadecanol; and

- mixtures thereof.

Advantageously, the hydrocarbon-based oil is apolar (thus formed solely from carbon and hydrogen atoms), and better still it is chosen from hydrocarbons.

The hydrocarbon-based oil is preferably chosen from hydrocarbon-based oils containing from 8 to 16 carbon atoms, more preferentially from 12 to 16 carbon atoms, and better still apolar oils.

Preferentially, the hydrocarbon-based oil is chosen from Cs to C _½ and preferably C12 to C _½ linear or branched alkanes, more preferentially chosen from Cs to Ci ₆ and preferably C12 to C½ branched alkanes. Particularly preferably, the hydrocarbon-based oil is isododecane. Preferably, the hydrocarbon-based oil(s) (3) present in the oily dispersion (A), and more preferentially when this oil is isododecane, constitute the only oil(s) of the oily dispersion (A), or are present in a majority content relative to the additional oils that may be present in the oily dispersion (A).

The total content of the hydrocarbon-based oil(s) (3) present in the oily dispersion (A) according to the invention preferably ranges from 20% to 90% by weight, more preferentially from 30% to 80% by weight, and better still from 40% to 70% by weight, relative to the total weight of the oily dispersion (A).

Without this being limiting, in general, the oily dispersion (A) according to the invention may be prepared in the following manner: the polymerization is performed in "dispersion" , i.e. by precipitation of the ethylenic copolymer during formation, with protection of the formed particles with one or more stabilizers, preferably with one stabilizer.

In a first step, the stabilizer b) is prepared by mixing the constituent monomer(s) of said stabilizer with a free-radical initiator, in a solvent known as the synthesis solvent, and by polymerizing said monomers.

In a second step, the constituent monomers of the ethylenic copolymer of the particles a) are added to the stabilizer thus formed in the preceding step and polymerization of said added monomers is performed in the presence of the free-radical initiator.

When the non-aqueous medium is a non-volatile hydrocarbon-based oil c), the polymerization may be performed in an apolar organic solvent (synthesis solvent), followed by adding the non-volatile hydrocarbon-based oil (which should be miscible with said synthesis solvent) and selectively distilling off the synthesis solvent.

When the dyestuff(s), chosen from colorants, pigments and mixtures thereof, are included in the oily dispersion (A), they may be added during the first step. According to another variant, said dyestuff(s) are added during the second step or after the second step.

A synthesis solvent in which the monomers of the stabilizer and the free- radical initiator are soluble, and in which the ethylenic copolymer particles obtained are insoluble so that they precipitate therein during their formation, is thus preferably chosen.

In particular, a synthesis solvent which is an apolar organic solvent is chosen, preferably chosen from alkanes such as heptane or cyclohexane. When the non-aqueous medium is a volatile hydrocarbon-based oil c), the polymerization may be performed directly in said oil, which thus also acts as synthesis solvent. The monomers of the stabilizer and the free-radical initiator must also be soluble therein, and the ethylenic copolymer of the particles obtained must be insoluble therein.

The monomers of the ethylenic copolymer are preferably present in the synthesis solvent, before polymerization, in a proportion of from 5% to 45% by weight, relative to the total weight of the reaction mixture. The total amount of said monomers may be present in the solvent before the start of the reaction, or a portion of said monomers may be added gradually as the polymerization reaction proceeds.

The polymerization is preferentially performed in the presence of one or more free -radical initiators, notably of the type such as:

- peroxide, in particular chosen from tert-butyl peroxy-2-ethylhexanoate: Trigonox 21S; 2,5-dimethyl-2,5-bis(2-ethylhexanoylperoxy)hexane:Trigonox 141; tert-butyl peroxypivalate: Trigonox 25C75 from AkzoNobel; or

- azo, in particular chosen from AIBN: azobisisobutyronitrile; V50: 2,2'- azobis (2- amidinoprop ane) dihydrochloride .

The polymerization is preferably performed at a temperature ranging from 70 to 110°C and at atmospheric pressure.

The ethylenic copolymer particles a) are surface-stabilized, during the polymerization, by means of the stabilizer b). The stabilization may be performed by any known means, and in particular by direct addition of the stabilizer b) during the polymerization.

The stabilizer ii) is preferably present in the mixture before polymerization of the monomers of the ethylenic copolymer a). However, it is also possible to add it continuously, notably when the monomers of the ethylenic copolymer a) are gradually added as the polymerization reaction proceeds.

From 10% to 30% by weight and preferably from 15% to 25% by weight of the stabilizer(s) a) may notably be used relative to the total weight of monomers used (stabilizers ii) + ethylenic copolymers i)).

According to a first embodiment, the oily dispersion (A) according to the invention is an anhydrous composition. The term " anhydrous ” composition refers to a dispersion composition containing less than 2% by weight of water, or even less than 0.5% of water, and notably free of water. Where appropriate, such small amounts of water may notably be introduced by ingredients of the composition that may contain residual amounts thereof.

According to a second embodiment, the dispersion (A) is in inverse emulsion form, i.e. of water-in-oil type (W/O). In this case, the composition comprises one or more surfactants, which are preferably nonionic.

The composition (B)

The cosmetic treatment process according to the present invention also comprises a step of applying to said keratin materials a composition (B) as defined previously.

Amino silicones

Composition (B) used in the cosmetic treatment process according to the present invention comprises one or more amino silicones (4).

The term “amino silicone” denotes any silicone including at least one primary, secondary or tertiary amine or a quaternary ammonium group.

The weight- average molecular masses of these amino silicones may be measured by gel permeation chromatography (GPC) at room temperature (25 °C), as polystyrene equivalent. The columns used are m styragel columns. The eluent is THF and the flow rate is 1 ml/min. 200 pi of a 0.5% by weight solution of silicone in THF are injected. Detection is performed by refractometry and UV-metry.

Throughout the text hereinbelow, the term “silicone” is intended to denote, in accordance with what is generally accepted, any organosilicon polymer or oligomer of linear or cyclic, branched or crosslinked structure, of variable molecular weight, obtained by polymerization and/or polycondensation of suitably functionalized silanes, and formed essentially from a repetition of main units in which the silicon atoms are linked together via oxygen atoms (siloxane bond -Si-O-Si-), optionally substituted hydrocarbon-based groups being directly linked via a carbon atom to said silicon atoms. The hydrocarbon-based groups that are the most common are alkyl groups, notably Ci-Cio alkyl groups and in particular methyl, fluoroalkyl groups, the alkyl part of which is Ci-Cio, and aryl groups and in particular phenyl.

The appropriate amino silicones (4) that may be used in accordance with the present invention comprise, without being limited thereto, volatile and non-volatile, cyclic, linear and branched amino silicones, with a viscosity ranging from 5xl0 ⁶ to 2.5 m ² /s at 25°C, for example from lxlO ⁵ to 1 m ² /s. Preferably, the amino silicone(s) (4) are chosen from: a) the polysiloxanes corresponding to formula (IV):

(IV) in which x' and y' are integers such that the weight- average molecular mass (Mw) is between 5000 and 500000 g/mol; b) the amino silicones corresponding to formula (V):

R'aG3-a-Si(0SiG ₂ )„-(0SiGbR'2-b)m-0-SiG3-a'-R'a' (V) in which:

- G, which may be identical or different, denotes a hydrogen atom or a phenyl group, OH group, or Ci-Cs alkyl group, for example methyl, or Ci-Cs alkoxy, for example methoxy,

- a and a’ , which may be identical or different, denote 0 or an integer from 1 to 3, in particular 0, with the proviso that at least one from among a and a' is equal to zero,

- b denotes 0 or 1, in particular 1,

- m and n are numbers such that the sum (n + m) ranges from 1 to 2000 and in particular from 50 to 150, n possibly denoting a number from 0 to 1999 and notably from 49 to 149, and m possibly denoting a number from 1 to 2000 and notably from 1 to 10; and

- R', which may be identical or different, denotes a monovalent radical of formula -C _q H2 _q L in which q is a number ranging from 2 to 8 and L is an optionally quaternized amino group chosen from the following groups:

^• -NR"-Q-N(R")2,

^• -N(R")2,

^• -N ⁺ (R")3 A-,

^• -N ⁺ H(R")2 A , • -N ⁺ H ₂ (R") A-,

• -NR"-Q-N ⁺ (R")H ₂ A ,

• -NR"-Q-N ⁺ (R")2H A- and

^• -NR"-Q-N ⁺ (R")3 A , in which R”, which may be identical or different, denotes hydrogen, phenyl, benzyl, or a saturated monovalent hydrocarbon-based radical, for example a Ci-C ₂ o alkyl radical; Q denotes a linear or branched group of formula C _r H _2r , r being an integer ranging from 2 to 6, preferably from 2 to 4; and A represents a cosmetically acceptable anion, notably a halide such as fluoride, chloride, bromide or iodide. According to a first embodiment, the amino silicones corresponding to formula (V) are chosen from the silicones known as "trimethylsilyl amodimethicone", corresponding to formula (VI):

(VI) in which m and n are numbers such that the sum (n + m) ranges from 1 to 2000 and in particular from 50 to 150, n possibly denoting a number from 0 to 1999 and notably from 49 to 149, and m possibly denoting a number from 1 to 2000 and notably from 1 to 10.

According to a second embodiment, the amino silicones corresponding to formula (V) are chosen from the silicones of formula (VII) below: in which:

- m and n are numbers such that the sum (n + m) ranges from 1 to 1000, notably from 50 to 250 and more particularly from 100 to 200; n denoting a number from 0 to 999 and notably from 49 to 249 and more particularly from 125 to 175, and m denoting a number from 1 to 1000, notably from 1 to 10 and more particularly from 1 to 5; and

- Ri, R ₂ and R ₃ , which may be identical or different, represent a hydroxyl or C ₁ -C ₄ alkoxy radical, at least one of the radicals Ri to R ₃ denoting an alkoxy radical. Preferably, the alkoxy radical is a methoxy radical.

The hydroxy /alkoxy mole ratio preferably ranges from 0.2:1 to 0.4:1 and preferably from 0.25:1 to 0.35:1 and more particularly is equal to 0.3:1.

The weight- average molecular mass (Mw) of these silicones preferably ranges from 2000 to 1 000000 g/mol and more particularly from 3500 to 200000 g/mol.

According to a third embodiment, the amino silicones corresponding to formula (V) are chosen from the silicones of formula (VIII) below: in which:

- p and q are numbers such that the sum (p + q) ranges from 1 to 1000, in particular from 50 to 350 and more particularly from 150 to 250; p denoting a number from 0 to 999, notably from 49 to 349 and more particularly from 159 to 239, and q denoting a number from 1 to 1000, notably from 1 to 10 and more particularly from 1 to 5; and

- Ri and R2, which are different, represent a hydroxyl or C1-C4 alkoxy radical, at least one of the radicals Ri or R2 denoting an alkoxy radical.

Preferably, the alkoxy radical is a methoxy radical.

The hydroxy /alkoxy mole ratio generally ranges from 1:0.8 to 1:1.1 and preferably from 1:0.9 to 1:1 and more particularly is equal to 1:0.95.

The weight- average molecular mass (Mw) of the silicone preferably ranges from 2000 to 200 000 g/mol, more preferentially from 5000 to 100 000 g/mol and in particular from 10000 to 50000 g/mol.

The commercial products comprising silicones of structure (VII) or (VIII) may include in their composition one or more other amino silicones, the structure of which is different from formula (VII) or (VIII).

A product containing amino silicones of structure (VII) is sold by the company Wacker under the name Belsil® ADM 652.

A product containing amino silicones of structure (VIII) is sold by Wacker under the name Fluid WR 1300®. Another product containing amino silicones of structure (VIII) is sold by Wacker under the name Belsil ADM LOG 1®.

When these amino silicones are used, one particularly advantageous embodiment consists in using them in the form of an oil-in-water emulsion. The oil- in- water emulsion may comprise one or more surfactants. The surfactants may be of any nature but are preferably cationic and/or nonionic. The number-average size of the silicone particles in the emulsion generally ranges from 3 nm to 500 nanometres. Preferably, notably as amino silicones of formula (VIII), use is made of microemulsions of which the mean particle size ranges from 5 nm to 60 nm (limits included) and more particularly from 10 nm to 50 nm (limits included). Thus, use may be made according to the invention of the amino silicone microemulsions of formula (VIII) sold under the names Finish CT 96 E® or SLM 28020® by the company Wacker.

According to a fourth embodiment, the amino silicones corresponding to formula (V) are chosen from the silicones of formula (IX) below: in which:

- m and n are numbers such that the sum (n + m) ranges from 1 to 2000 and in particular from 50 to 150, n denoting a number from 0 to 1999 and notably from 49 to 149, and m denoting a number from 1 to 2000 and notably from 1 to 10; and

- A denotes a linear or branched alkylene radical containing from 4 to 8 carbon atoms and preferably 4 carbon atoms. This radical is preferably linear.

The weight- average molecular mass (Mw) of these amino silicones preferably ranges from 2000 to 1 000 000 g/mol and more particularly from 3500 to 200 000 g/mol.

A silicone corresponding to this formula is, for example, the Xiameter MEM 8299 Emulsion from Dow Coming.

According to a fifth embodiment, the amino silicones corresponding to formula (V) are chosen from the silicones of formula (X) below: in which: - m and n are numbers such that the sum (n + m) ranges from 1 to 2000 and in particular from 50 to 150, n possibly denoting a number from 0 to 1999 and notably from 49 to 149, and m possibly denoting a number from 1 to 2000 and notably from 1 to 10; and - A denotes a linear or branched alkylene radical containing from 4 to 8 carbon atoms and preferably 4 carbon atoms. This radical is preferably branched.

The weight- average molecular mass (Mw) of these amino silicones preferably ranges from 500 to 1 000000 g/mol and more particularly from 1000 to 200000 g/mol. A silicone corresponding to this formula is, for example, DC2-8566 Amino Fluid from Dow Coming; c) the amino silicones corresponding to formula (XI): in which: - R5 represents a monovalent hydrocarbon-based radical containing from 1 to

18 carbon atoms, and in particular a Ci-Cis alkyl or C2-C18 alkenyl, for example methyl, radical;

- R ₆ represents a divalent hydrocarbon-based radical, notably a Ci-Cis alkylene radical or a divalent Ci-Cis, for example Ci-Cs, alkyleneoxy radical linked to the Si via an SiC bond;

- Q is an anion such as a halide ion, notably chloride, or an organic acid salt, notably acetate;

- r represents a mean statistical value ranging from 2 to 20 and in particular from 2 to 8; and - s represents a mean statistical value ranging from 20 to 200 and in particular from 20 to 50.

Such amino silicones are notably described in patent US 4 185087. d) the quaternary ammonium silicones of formula (XII):

(XII) in which:

- R7, which may be identical or different, represent a monovalent hydrocarbon-based radical containing from 1 to 18 carbon atoms, and in particular a

C1-C18 alkyl radical, a C2-C18 alkenyl radical or a ring comprising 5 or 6 carbon atoms, for example methyl;

- R ₆ represents a divalent hydrocarbon-based radical, notably a Ci-Cis alkylene radical or a divalent Ci-Cis, for example Ci-Cs, alkyleneoxy radical linked to the Si via an SiC bond;

- Rs, which may be identical or different, represent a hydrogen atom, a monovalent hydrocarbon-based radical containing from 1 to 18 carbon atoms, and in particular a Ci-Cis alkyl radical, a C ₂ -C ₁₈ alkenyl radical or a radical -R ₆ -NHCOR ₇ ;

- X is an anion such as a halide ion, notably chloride, or an organic acid salt, notably acetate; and

- r represents a mean statistical value ranging from 2 to 200 and in particular from 5 to 100.

Such amino silicones are notably described in patent application EP-A 0 530

974. e) the amino silicones of formula (XIII):

(XIII) in which:

- Ri, R ₂ , R ₃ and R ₄ , which may be identical or different, denote a C1-C4 alkyl radical or a phenyl group,

- R5 denotes a C1-C4 alkyl radical or a hydroxyl group, - n is an integer ranging from 1 to 5,

- m is an integer ranging from 1 to 5, and

- x is chosen such that the amine number ranges from 0.01 to 1 meq/g; f) multiblock polyoxyalkylene amino silicones, of the type (AB) _n , A being a polysiloxane block and B being a polyoxyalkylene block including at least one amine group.

Said silicones are preferably formed from repeating units having the following general formulae:

[-(SiMe ₂ 0) _x SiMe ₂ -R-N(R")-R'-0(C ₂ H ₄ 0) _a (C ₃ H ₆ 0) _b -R'-N(H)-R-] or alternatively

[-(SiMe ₂ 0)xSiMe2-R-N(R")-R'-0(C2H40)a(C3H ₆ 0)b-] in which:

- a is an integer greater than or equal to 1, preferably ranging from 5 to 200 and more particularly ranging from 10 to 100;

- b is an integer between 0 and 200, preferably ranging from 4 to 100 and more particularly between 5 and 30;

- x is an integer ranging from 1 to 10 000 and more particularly from 10 to

5000;

- R” is a hydrogen atom or a methyl;

- R, which may be identical or different, represent a linear or branched divalent C2-C12 hydrocarbon-based radical, optionally including one or more heteroatoms such as oxygen; preferably, R, which may be identical or different, denote an ethylene radical, a linear or branched propylene radical, a linear or branched butylene radical or a CH ₂ CH ₂ CH ₂ 0CH ₂ CH(0H)CH ₂ - radical; preferentially, R denote a CH ₂ CH ₂ CH ₂ 0CH ₂ CH(0H)CH ₂ - radical; and

- R’, which may be identical or different, represent a linear or branched divalent C2-C12 hydrocarbon-based radical, optionally including one or more heteroatoms such as oxygen; preferably, R’, which may be identical or different, denote an ethylene radical, a linear or branched propylene radical, a linear or branched butylene radical or a CH ₂ CH ₂ CH ₂ 0CH ₂ CH(0H)CH ₂ - radical; preferentially, R’ denote -CH(CH )-CH ₂ -.

The siloxane blocks preferably represent between 50 mol% and 95 mol% of the total weight of the silicone, more particularly from 70 mol% to 85 mol%.

The amine content is preferably between 0.02 and 0.5 meq/g of copolymer in a 30% solution in dipropylene glycol, more particularly between 0.05 and 0.2. The weight- average molecular mass (Mw) of the silicone is preferably between 5000 and 1 000000 g/mol and more particularly between 10000 and 200000 g/mol.

Mention may notably be made of the silicones sold under the name Silsoft A- 843 or Silsoft A+ by Momentive. g) the amino silicones of formulae (XIV) and (XV):

(XIV) in which: - R, R’ and R”, which may be identical or different, denote a C1-C4 alkyl group or a hydroxyl group,

- A denotes a C3 alkylene radical; and

- m and n are numbers such that the weight- average molecular mass of the compound is between 5000 and 500000; in which:

- x and y are numbers ranging from 1 to 5000; preferably, x ranges from 10 to 2000 and more preferentially from 100 to 1000; preferably, y ranges from 1 to 100; - Ri and R2, which may be identical or different, preferably identical, denote a linear or branched, saturated or unsaturated alkyl group comprising from 6 to 30 carbon atoms, preferably from 8 to 24 carbon atoms and more preferentially from 12 to 20 carbon atoms; and

- A denotes a linear or branched alkylene radical containing from 2 to 8 carbon atoms.

Preferably, A comprises from 3 to 6 carbon atoms, more preferentially 4 carbon atoms; preferably, A is branched.

Mention may be made in particular of the following divalent groups: -CH2CH2CH2- and -CH ₂ CH(CH )CH ₂ -.

Preferably, Ri and R2 are independent saturated linear alkyl groups comprising 6 to 30 carbon atoms, preferably 8 to 24 carbon atoms and in particular from 12 to 20 carbon atoms; mention may be made in particular of dodecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl and eicosyl groups; and preferentially, Ri and R2, which may be identical or different, are chosen from hexadecyl (cetyl) and octadecyl (stearyl) groups.

The amino silicone(s) are preferably of formula (XV) with:

- x ranging from 10 to 2000 and in particular from 100 to 1000;

- y ranging from 1 to 100;

- A comprising from 3 to 6 carbon atoms and notably 4 carbon atoms; preferably, A is branched; more particularly, A is chosen from the following divalent groups: -CH2CH2CH2- and -CH ₂ CH(CH ₃ )CH ₂ -; and

- Ri and R2 independently being saturated linear alkyl groups comprising from 6 to 30 carbon atoms, preferably from 8 to 24 carbon atoms and in particular from 12 to 20 carbon atoms; chosen notably from dodecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl and eicosyl groups; preferentially, Ri and R2, which may be identical or different, are chosen from hexadecyl (cetyl) and octadecyl (stearyl) groups.

A silicone of formula (XV) that is preferred is bis-cetearyl amodimethicone. Mention may be made in particular of the amino silicone sold under the name Silsoft AX by Momentive. h) polysiloxanes and notably polydimethylsiloxanes, including primary amine groups at only one chain end or on side chains, such as those of formula (XVI), (XVII) or (XVIII):

(XVIII)

In formula (XVI), the values of n and m are such that the weight- average molecular mass of the amino silicone is between 1000 and 55000.

As examples of amino silicones of formula (XVI), mention may be made of the products sold under the names AMS- 132, AMS- 152, AMS- 162, AMS- 163, AMS- 191 and AMS- 1203 by the company Gelest and KF-8015 by the company Shin-Etsu.

In formula (XVII), the value of n is such that the weight-average molecular mass of the amino silicone is between 500 and 3000.

As examples of amino silicones of formula (XVII), mention may be made of the products sold under the names MCR-A11 and MCR-A12 by the company Gelest.

In formula (XVIII), the values of n and m are such that the weight- average molecular mass of the amino silicone is between 500 and 50000. As examples of amino silicones of formula (XVIII), mention may be made of the aminopropyl phenyl trimethicone sold under the name DC 2-2078 Fluid by the company Dow Coming. i) and mixtures thereof.

Preferably, the amino silicone(s) (4) are chosen from the amino silicones of formula (XVI) and mixtures thereof, and better still the amino silicone (4) is bis- cetearyl amodimethicone.

The content of the amino silicone(s) (4) present in composition (B) according to the present invention preferably ranges from 0.5% to 15% by weight, preferentially from 1% to 10% by weight, relative to the total weight of composition (B).

The polysaccharides bearing amine group(s)

Composition (B) used in the cosmetic treatment process according to the present invention also comprises (5) one or more polysaccharides bearing amine group(s), and also the organic or mineral acid salts thereof, the a or b anomers thereof, the optical isomers thereof of L or D configuration and the solvates thereof such as hydrates.

Preferably, the polysaccharide(s) bearing amine group(s) (5) have an average molecular weight (MW) of less than or equal to 400 kDa and more preferentially less than 200 kDa.

Advantageously, the polysaccharide(s) bearing amine group(s) (5) have a low average molecular weight MW, i.e. they have a molecular weight of less than 100 kDa.

The polysaccharide(s) bearing amine group(s) (5) are preferably of natural animal or plant origin, or else are derived from synthesis, semisynthesis or biosynthesis.

According to a particular embodiment of the invention, the polysaccharide(s) bearing amine group(s) (5) are chosen from polysaccharides containing C5-C7 saccharide units bearing amine group(s), and also the organic or mineral acid salts thereof, the a or b anomers thereof, the optical isomers thereof of L or D configuration, and the solvates thereof such as hydrates, and mixtures thereof.

More particularly, the polysaccharide(s) bearing amine group(s) (5) contain a Ce saccharide unit bearing amine group(s); these polysaccharides bearing amine group(s) are then referred to as polyhexosamines. According to a particular embodiment, the saccharide units of the polysaccharide bearing amine group(s) (5) are of b (beta) anomeric configuration and/or D configuration.

According to a particular embodiment, the saccharide units of the polysaccharide bearing amine group(s) (5) are connected together between the atoms of carbon 1 of one saccharide unit and of carbon 4 of the other saccharide unit, denoted

(1 4).

According to this embodiment, the polysaccharide(s) bearing amine group(s) (5) are preferably chosen from polysaccharides containing a saccharide unit of formula (XIX) below, and also the organic or mineral acid salts thereof, the a or b anomers thereof, the optical isomers thereof of L or D configuration, and the solvates thereof such as hydrates, and mixtures thereof: in which formula (XIX):

- n is an integer greater than or equal to 2, particularly between 3 and 3000 inclusive, and more particularly between 5 and 2500, preferentially between 10 and 2300;

- R _a , R _b and R _c , which may be identical or different for each saccharide unit, represent (1) a hydroxyl group, (2) a (Ci-C4)alkoxy group, the alkyl chain of which may be optionally substituted notably with one or more hydroxyl and/or carboxyl groups, (3) a carboxyl group, or (4) a group NR1R2 with Ri and R2, which may be identical or different, representing i) a hydrogen atom, ii) a (Ci-C ₆ )alkyl group that is optionally substituted, preferably with one or more hydroxyl or Nth groups, iii) an aryl group such as phenyl, iv) an aryl(Ci-C4)alkyl group such as benzyl, v) a (hetero)cyclo(C5-C7)alkyl group such as cyclohexyl, morpholinyl, piperazinyl or piperidyl, vi) a (hetero)cyclo(C5-C7)alkyl(Ci-C4)alkyl group such as cyclohexylmethyl, vii) a group -C(Y)-(Y') _p -R'i with Y and Y', which may be identical or different, representing an oxygen atom, a sulfur atom or N(Rh), preferably oxygen, p = 0 or 1, preferably 0; and R'i and R'2 representing i) to vi) of Ri and R2 defined previously, and in particular R'i denoting a (Ci-C ₆ )alkyl group such as methyl; it being understood that at least one of the radicals R _a , R _b or R _c of at least one saccharide unit represents a group NR1R2 and that at least one of the groups NR1R2 of at least one saccharide unit represents an NH2 group.

Preferably, Ri and R2 are chosen from a hydrogen atom and -C(0)-R’i in which R’i is as defined previously; and more preferentially Ri and R2 represent i) a hydrogen atom or ii) -C(0)-R’i, with R’i representing a (Ci-C4)alkyl group such as methyl. Preferably, R _a of at least one saccharide unit represents a group NR1R2 with

Ri which represents a hydrogen atom and R2 chosen from i) a hydrogen atom or ii) a group -C(0)-R’i, and R _b and R _c represent a hydroxyl group, it being understood that at least one of the groups NR1R2 of at least one saccharide unit represents an NH2 group. More particularly, the polysaccharide(s) bearing amine group(s) (5) are chosen from polysaccharides containing saccharide units of formula (XlXa) below, and also the organic or mineral acid salts thereof, the a or b anomers thereof, the optical isomers thereof of L or D configuration, and the solvates thereof such as hydrates, and mixtures thereof: in which formula (XlXa):

- R’ represents a hydrogen atom or a (Ci -Chalky lcarbonyl group such as acetyl CH -C(0)-; - R” represents a hydrogen atom or a (Ci-C4)alkyl group optionally substituted with a carboxyl group such as -CH(C02H)-CH3;

- n is an integer greater than or equal to 2, preferably between 3 and 3000, more preferentially between 5 and 2500, and better still between 10 and 2300; it being understood that at least one saccharide unit bears an Nth amino group and at least one other saccharide unit bears at least one group N(H)-R' with R' representing a (Ci -Chalky lcarbonyl group such as acetyl Cth-C(O)-.

Preferably, the saccharide units of formula (XIX) or (XlXa) are of D configuration, also referred to as D-glucopyran.

Particularly, the saccharide units of formula (XIX) or (XlXa) are of b (beta) anomeric configuration.

According to a particular embodiment, the polysaccharides (5) are chosen from the polysaccharides containing a saccharide unit of formula (XlXb) below and also the organic or mineral acid salts thereof, and the solvates thereof such as hydrates, and mixtures thereof:

(XlXb) in which: - R _a , R _b and R _c are as defined for (XIX) previously; and the radicals R _a , R _b and R _c of each saccharide unit may be identical or different; and

- n is an integer greater than or equal to 2, preferably between 3 and 3000, more preferentially between 5 and 2500, and better still between 10 and 2300; it being understood that at least one of the radicals R _a , R _b or R _c of at least one saccharide unit represents a group NR1R2, with Ri and R2 as defined previously for (XIX), and that at least one of the groups NR1R2 of at least one saccharide unit represents an NH2 group; preferably, at least one saccharide unit bears a group R _a representing an Nth group and at least one other saccharide unit bears a group R _a representing a group -N(H)-R' with R' representing a (Ci -Chalky lcarbonyl group such as acetyl Ctb-C(O)-.

Preferably, the polysaccharide(s) bearing amine group(s) (5) are chosen from chitin and chitosan, and derivatives thereof, and more preferentially chitosan.

More particularly, the polysaccharide(s) bearing amine group(s) (5) are chosen from polysaccharides containing a saccharide unit of formula (XIXc) below, and also the organic or mineral acid salts thereof, and the solvates thereof such as hydrates, and mixtures thereof:

(XIXc) in which formula (XIXc):

- Ri and R2 are as defined in formulae (XIX) and (XlXb); and

- n is an integer greater than or equal to 2, preferably between 3 and 3000, more preferentially between 5 and 2500, and better still between 10 and 2300; it being understood that at least one saccharide unit bears an Nth amino group and at least one other saccharide unit bears a group N(H)-R' with R' representing a (Ci- C4)alkylcarbonyl group such as acetyl ϋ¾-(3(0)-.

More particularly, the polysaccharide(s) bearing amine group(s) (5) are chosen from the chitosans of formula (XlXd) below, and also the organic or mineral acid salts thereof, the solvates thereof such as hydrates, and mixtures thereof:

(XlXd) in which formula (XlXd):

- R'i represents a (Ci-C4)alkyl group such as methyl; and

- n is an integer greater than or equal to 2, preferably between 3 and 3000, more preferentially between 5 and 2500, and better still between 10 and 2300; - p is greater than 0 and ranges up to 0.5, preferably from 0.05 to 0.3, and better still from 0.1 to 0.20 such as 0.15 with m+p being equal to 1; it being understood that, in the chitosan, at least one saccharide unit bears an amino group Nth and at least one other saccharide unit bears a group N(H)-R’i with R’i representing a (Ci -Chalky lcarbonyl group such as acetyl ϋ¾-(3(0)-.

For example, when m = 0.7 and p = 0.3, this means that 70% of the amine groups are free (unsubstituted) and 30% of the amino groups are N-alkyl(Ci- C4)carbonyl groups, in particular N-acetyl groups, corresponding to the chitosan polymer of formula: with n as defined previously.

Preferably, the polysaccharide(s) bearing amine group(s) (B2) are salified, or are in salified form, using one or more organic or mineral acids, and preferably using one or more organic acids. The organic or mineral acid(s) that may be used correspond to the mineral and organic acids described previously in the section "organic or mineral acid salt".

Preferably, the polysaccharide(s) bearing amine group(s) (5) are salified using one or more organic acid(s) chosen from:

- the monocarboxylic acids of formula (XX): R-C(0)-OH (XX) in which formula (XX) R represents a (hetero)aryl radical such as phenyl, a (hetero)aryl(Ci-C4)alkyl radical such as benzyl, a (Ci-C3o)alkyl radical or an unsaturated C2-C30 radical (i.e. including at least one ethylenic unsaturation, preferably one ethylenic unsaturation), said alkyl or unsaturated C2-C30 radical being optionally interrupted and/or optionally substituted preferably with one or more hydroxyl groups and not substituted with one or more amino radicals; R preferably denoting a (Ci- C ₆ )alkyl group optionally interrupted and/or optionally substituted with 1, 2 or 3 hydroxyl groups; preferably, R represents a (Ci-C4)alkyl group such as methyl or ethyl; - the polycarboxylic acids of formula (XXI): (XXI) in which formula (XXI) A represents a saturated or unsaturated, cyclic or non- cyclic, aromatic or non-aromatic polyvalent hydrocarbon-based group comprising from 1 to 30 carbon atoms, optionally interrupted with one or more heteroatoms such as oxygen and/or optionally substituted notably with one or more hydroxyl groups and t represents an integer between 1 and 5 inclusive; preferably, A represents a divalent (Ci-C ₆ )alkylene group optionally substituted notably with one or more hydroxyl groups and not substituted with at least t amino radicals, and t is equal to 1, 2 or 3; and

- amino acids including more carboxylic acid radicals than amino groups.

Preferably, the monocarboxylic organic acids of formula (XX) are chosen from acetic acid, glycolic acid, lactic acid, and mixtures thereof, and more preferentially from acetic acid, lactic acid, and mixtures thereof.

Preferably, the polycarboxylic acids of formula (XXI) are chosen from tartaric acid, succinic acid, fumaric acid, maleic acid, citric acid, and mixtures thereof.

Preferably, the amino acids including more carboxylic acid radicals than amino groups are chosen from gamma-carboxyglutamic acid, aspartic acid, glutamic acid, and mixtures thereof, and more preferentially gamma-carboxyglutamic acid.

More preferentially, the organic acid(s) that may be used are chosen from acetic acid, glycolic acid, lactic acid, tartaric acid, succinic acid, fumaric acid, maleic acid, citric acid, gamma-carboxyglutamic acid, aspartic acid, glutamic acid, and mixtures thereof, and preferably, the organic acid is lactic acid.

Particularly, the polysaccharide(s) bearing amine group(s) (5) are chosen from chitosans, salified using organic acid, preferentially using monocarboxylic acid of formula (XX) as defined previously or polycarboxylic acid of formula (XXI) as defined previously, even more preferentially salified using carboxylic acid of formula (XX) such as lactic acid.

Preferably, the polysaccharide(s) bearing amine group(s) (5) denote a single polysaccharide bearing amine group(s), in particular a chitosan or the organic or mineral acid salts thereof or more particularly the organic acid salts thereof such as the lactic acid salt thereof, the a or b anomers thereof, the optical isomers thereof of L or D configuration, and the solvates thereof such as hydrates.

The total content of the polysaccharide(s) bearing amine group(s) (5) present in composition (B) according to the present invention preferably ranges from 0.1% to 15% by weight and preferentially from 0.5% to 10% by weight relative to the total weight of composition (B).

The weight ratio between the total content of polysaccharides bearing amine group(s) (5) and the total content of amino silicone (4), present in composition (B) of the invention, preferably ranges from 0.1 to 5 and more preferentially from 0.1 to 2.

According to a particular embodiment of the invention, composition (B) also comprises one or more hydrocarbon-based oils as defined previously. Advantageously, the hydrocarbon-based oils contained in the oily dispersion (A) and in composition (B) are identical.

According to a preferred embodiment of the invention, the hydrocarbon-based oil(s) of composition (B) are chosen from hydrocarbon-based oils containing from 8 to 14 carbon atoms, in particular the apolar oils described previously. More preferentially, the hydrocarbon-based oil(s) of composition (B) are isododecane.

According to a particular embodiment of the invention, composition (B) is aqueous or aqueous -alcoholic, preferably aqueous. The term "aqueous-alcoholic" refers to a mixture of water and of a linear or branched C2 to C4 alkanol, preferably water and ethanol.

The dyestuffs

The cosmetic treatment process according to the present invention also involves (6) one or more dyestuffs chosen from colorants, pigments and mixtures thereof, said dyestuffs being present in the oily dispersion (A) and/or in composition (B) and/or in another composition (C).

Preferably, the dyestuff(s) are chosen from colorants, and more particularly from hair dyes.

The term “hair dyes" refers to oxidation dyes, direct dyes and direct dyes used for dyeing keratin fibres, notably human keratin fibres such as the hair.

Among the hair dyes that may be mentioned are:

- oxidation dyes, which are generally chosen from one or more oxidation bases, optionally combined with one or more coupling agents.

By way of example, the oxidation bases are chosen from para- phenylenediamines, bis(phenyl)alkylenediamines, para-aminophenols, ortho- aminophenols and heterocyclic bases and the corresponding addition salts, optionally combined with coupling agents; they may particularly be chosen from meta- phenylenediamines, meta-aminophenols, meta-diphenols, naphthalene-based coupling agents and heterocyclic coupling agents and also the corresponding addition salts;

- direct dyes, notably azo direct dyes; (poly)methine dyes such as cyanines, hemicyanines and styryls; carbonyl dyes; azine dyes; nitro(hetero)aryl dyes; tri(hetero)arylmethane dyes; porphyrin dyes; phthalocyanine dyes and natural direct dyes, alone or in the form of mixtures. The direct dyes may be anionic, cationic or neutral.

- natural dyes, notably chosen from hennotannic acid, juglone, alizarin, purpurin, carminic acid, kermesic acid, purpurogallin, protocatechaldehyde, indigo, isatin, curcumin, spinulosin, apigenidin and orcein, and also extracts or decoctions containing these natural dyes.

Preferably, the dyestuff(s) are chosen from pigments and mixtures thereof.

The term “pigment” refers to any pigment, of synthetic or natural origin, which gives colour to keratin materials. The solubility of the pigments in water at 25 °C and at atmospheric pressure (760 mmHg) is less than 0.05% by weight, and preferably less than 0.01% by weight.

They are white or coloured solid particles which are naturally insoluble in the hydrophilic and lipophilic liquid phases usually employed in cosmetics or which are rendered insoluble by formulation in the form of a lake, where appropriate. More particularly, the pigments have little or no solubility in aqueous-alcoholic media.

The pigments that may be used are notably chosen from the organic and/or mineral pigments known in the art, notably those described in Kirk-Othmer’s Encyclopedia of Chemical Technology and in Ullmann’s Encyclopedia of Industrial Chemistry. Pigments that may notably be mentioned include organic and mineral pigments such as those defined and described in Ullmann's Encyclopedia of Industrial Chemistry "Pigments, organic", 2005 Wiley- VCH Verlag GmbH & Co. KGaA, Weinheim 10.1002/14356007. a20 371 and ibid, "Pigments, Inorganic, 1. General" 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim 10.1002/ 14356007.a20_243.pub3.

These pigments may be in pigment powder or paste form. They may be coated or uncoated. The pigments may be chosen, for example, from mineral pigments, organic pigments, lakes, pigments with special effects such as nacres or glitter flakes, and mixtures thereof.

The pigment may be a mineral pigment. The term “mineral pigment” refers to any pigment that satisfies the definition in Ullmann’s encyclopaedia in the chapter on inorganic pigments. Among the mineral pigments that are useful in the present invention, mention may be made of iron oxides, chromium oxides, manganese violet, ultramarine blue, chromium hydrate, ferric blue and titanium oxide.

The pigment may be an organic pigment. The term “organic pigment” refers to any pigment that satisfies the definition in Ullmann’s encyclopaedia in the chapter on organic pigments. The organic pigment may notably be chosen from nitroso, nitro, azo, xanthene, quinoline, anthraquinone, phthalocyanine, metal complex type, isoindolinone, isoindoline, quinacridone, perinone, perylene, diketopyrrolopyrrole, thioindigo, dioxazine, triphenylmethane and quinophthalone compounds.

In particular, the white or coloured organic pigments may be chosen from carmine, carbon black, aniline black, azo yellow, quinacridone, phthalocyanine blue, sorghum red, the blue pigments codified in the Colour Index under the references Cl 42090, 69800, 69825, 73000, 74100, 74160, the yellow pigments codified in the Colour Index under the references Cl 11680, 11710, 15985, 19140, 20040, 21100, 21108, 47000, 47005, the green pigments codified in the Colour Index under the references Cl 61565, 61570, 74260, the orange pigments codified in the Colour Index under the references Cl 11725, 15510, 45370, 71105, the red pigments codified in the Colour Index under the references Cl 12085, 12120, 12370, 12420, 12490, 14700, 15525, 15580, 15620, 15630, 15800, 15850, 15865, 15880, 17200, 26100, 45380, 45410, 58000, 73360, 73915, 75470, the pigments obtained by oxidative polymerization of indole or phenolic derivatives as described in patent FR 2 679771.

According to a particular embodiment of the invention, the pigment(s) used are pigment pastes of organic pigments such as the products sold by the company Hoechst under the name:

- Cosmenyl Yellow IOG: Yellow 3 pigment (Cl 11710);

- Cosmenyl Yellow G: Yellow 1 pigment (Cl 11680);

- Cosmenyl Orange GR: Orange 43 pigment (Cl 71105);

- Cosmenyl Red R: Red 4 pigment (Cl 12085);

- Cosmenyl Carmine FB: Red 5 pigment (Cl 12490);

- Cosmenyl Violet RL: Violet 23 pigment (Cl 51319); - Cosmenyl Blue A2R: Blue 15.1 pigment (Cl 74160);

- Cosmenyl Green GG: Green 7 pigment (Cl 74260);

- Cosmenyl Black R: Black 7 pigment (Cl 77266).

The pigments in accordance with the invention may also be in the form of composite pigments, as described in patent EP 1 184 426. These composite pigments may be composed notably of particles including:

- a mineral core,

- at least one binder for fixing the organic pigments to the core, and

- at least one organic pigment at least partially covering the core.

The term “lake” refers to dyes adsorbed onto insoluble particles, the assembly thus obtained remaining insoluble during use. The mineral substrates onto which the dyes are adsorbed are, for example, alumina, silica, calcium sodium borosilicate or calcium aluminium borosilicate and aluminium. Among the organic dyes, mention may be made of cochineal carmine.

Examples of lakes that may be mentioned include the products known under the following names: D & C Red 21 (Cl 45 380), D & C Orange 5 (Cl 45 370), D & C Red 27 (Cl 45 410), D & C Orange 10 (Cl 45 425), D & C Red 3 (Cl 45 430), D & C Red 7 (Cl 15 850:1), D & C Red 4 (Cl 15 510), D & C Red 33 (Cl 17 200), D & C Yellow 5 (Cl 19 140), D & C Yellow 6 (Cl 15 985), D & C Green (Cl 61 570), D & C Yellow 10 (Cl 77 002), D & C Green 3 (Cl 42 053) or D & C Blue 1 (Cl 42 090).

The mineral substrates onto which the dyes are adsorbed are, for example, alumina, silica, calcium sodium borosilicate or calcium aluminium borosilicate and aluminium.

Among the dyes, mention may be made of cochineal carmine. Mention may also be made of the dyes known under the following names: D & C Red 21 (Cl 45 380), D & C Orange 5 (Cl 45 370), D & C Red 27 (Cl 45 410), D & C Orange 10 (Cl 45 425), D & C Red 3 (Cl 45 430), D & C Red 4 (Cl 15 510), D & C Red 33 (Cl 17 200), D & C Yellow 5 (Cl 19 140), D & C Yellow 6 (Cl 15 985), D & C Green (Cl 61 570), D & C Yellow 10 (Cl 77 002), D & C Green 3 (Cl 42053), D & C Blue 1 (Cl 42 090).

An example of a lake that may be mentioned is the product known under the following name: D & C Red 7 (Cl 15 850:1).

The pigment(s) may also be pigments with special effects.

The term “pigments with special effects” means pigments that generally create a coloured appearance (characterized by a certain shade, a certain vivacity and a certain level of luminance) that is non-uniform and that changes as a function of the conditions of observation (light, temperature, angles of observation, etc.). They thereby differ from coloured pigments, which afford a standard uniform opaque, semi transparent or transparent shade.

Several types of pigments with special effects exist: those with a low refractive index, such as fluorescent, photochromic or thermochromic pigments, and those with a higher refractive index, such as nacres or glitter flakes.

Examples of pigments with special effects that may be mentioned include nacreous pigments such as titanium mica coated with an iron oxide, mica coated with an iron oxide, mica coated with bismuth oxychloride, titanium mica coated with chromium oxide, titanium mica coated with an organic dye notably of the abovementioned type, and also nacreous pigments based on bismuth oxychloride. They may also be mica particles, at the surface of which are superposed at least two successive layers of metal oxides and/or of organic dyestuffs.

The nacres may more particularly have a yellow, pink, red, bronze, orange, brown, gold and/or coppery colour or tint.

As illustrations of nacres that may be used in the context of the present invention, mention may notably be made of the gold-coloured nacres sold notably by the company BASF under the name Gold 222C (Cloisonne), Sparkle gold (Timica), Gold 4504 (Chromalite) and Monarch gold 233X (Cloisonne); the bronze nacres sold notably by the company Merck under the names Bronze fine (17384) (Colorona) and Bronze (17353) (Colorona), by the company Eckart under the name Prestige Bronze and by the company BASF under the name Super bronze (Cloisonne); the orange nacres sold notably by the company BASF under the names Orange 363C (Cloisonne) and Orange MCR 101 (Cosmica) and by the company Merck under the names Passion orange (Colorona) and Matte orange (17449) (Microna); the brown-tinted nacres sold notably by the company BASF under the names Nu-antique copper 340XB (Cloisonne) and Brown CF4509 (Chromalite); the nacres with a copper tint sold notably by the company BASF under the name Copper 340A (Timica) and by the company Eckart under the name Prestige Copper; the nacres with a red tint sold notably by the company Merck under the name Sienna fine (17386) (Colorona); the nacres with a yellow tint sold notably by the company BASF under the name Yellow (4502) (Chromalite); the red-tinted nacres with a golden tint sold notably by the company BASF under the name Sunstone GO 12 (Gemtone); the black nacres with a golden tint sold notably by the company BASF under the name Nu-antique bronze 240 AB (Timica); the blue nacres sold notably by the company Merck under the name Matte blue (17433) (Microna), Dark Blue (117324) (Colorona); the white nacres with a silvery tint sold notably by the company Merck under the name Xirona Silver; and the golden-green pinkish-orange nacres sold notably by the company Merck under the name Indian summer (Xirona), and mixtures thereof.

In addition to nacres on a mica support, multilayer pigments based on synthetic substrates such as alumina, silica, sodium calcium borosilicate or calcium aluminium borosilicate, and aluminium, may be envisaged.

Mention may also be made of pigments with an interference effect which are not attached to a substrate, such as liquid crystals (Helicones HC from Wacker) or interference holographic glitter flakes (Geometric Pigments or Spectra f/x from Spectratek). Pigments with special effects also comprise fluorescent pigments, whether these are substances that are fluorescent in daylight or that produce an ultraviolet fluorescence, phosphorescent pigments, photochromic pigments, thermochromic pigments and quantum dots, sold, for example, by the company Quantum Dots Corporation.

The variety of pigments that may be used in the present invention makes it possible to obtain a wide range of colours, and also particular optical effects such as metallic effects or interference effects.

The size of the pigment used in the cosmetic composition according to the present invention is generally between 10 nm and 200 pm, preferably between 20 nm and 80 pm and more preferably between 30 nm and 50 pm.

The pigments may be dispersed in the product by means of a dispersant.

The term "dispersant" refers to a compound which can protect the dispersed particles from agglomerating or flocculating. This dispersant may be a surfactant, an oligomer, a polymer or a mixture of several thereof, bearing one or more functionalities with strong affinity for the surface of the particles to be dispersed. In particular, they may become physically or chemically attached to the surface of the pigments. These dispersants also contain at least one functional group that is compatible with or soluble in the continuous medium. Said agent may be charged: it may be anionic, cationic, zwitterionic or neutral.

According to a particular embodiment of the invention, the dispersants used are chosen from esters of 12-hydroxystearic acid esters more particularly and of C8 to C20 fatty acids and of polyols such as glycerol or diglycerol, such as poly (12- hydroxystearic acid) stearate with a molecular weight of approximately 750 g/mol, such as the product sold under the name Solsperse 21 000 by the company Avecia, polyglyceryl-2 dipoly hydroxy stearate (CTFA name) sold under the reference Dehymyls PGPH by the company Henkel, or polyhydroxystearic acid such as the product sold under the reference Arlacel P100 by the company Uniqema, and mixtures thereof.

As other dispersants that may be used in the compositions of the invention, mention may be made of quaternary ammonium derivatives of polycondensed fatty acids, for instance Solsperse 17 000 sold by the company Avecia, and polydimethylsiloxane/oxypropylene mixtures such as those sold by the company Dow Coming under the references DC2-5185 and DC2-5225 C.

The pigments used in the cosmetic composition according to the invention may be surface-treated with an organic agent.

Thus, the pigments that have been surface-treated beforehand, which are useful in the context of the invention, are pigments that have totally or partially undergone a surface treatment of chemical, electronic, electrochemical, mechanochemical or mechanical nature, with an organic agent such as those described notably in Cosmetics and Toiletries, February 1990, Vol. 105, pages 53-64, before being dispersed in the composition in accordance with the invention. These organic agents may be chosen, for example, from amino acids; waxes, for example carnauba wax and beeswax; fatty acids, fatty alcohols and derivatives thereof, such as stearic acid, hydroxystearic acid, stearyl alcohol, hydroxystearyl alcohol and lauric acid and derivatives thereof; anionic surfactants; lecithins; sodium, potassium, magnesium, iron, titanium, zinc or aluminium salts of fatty acids, for example aluminium stearate or laurate; metal alkoxides; polysaccharides, for example chitosan, cellulose and derivatives thereof; polyethylene; (meth)acrylic polymers, for example polymethyl methacrylates; polymers and copolymers containing acrylate units; proteins; alkanolamines; silicone compounds, for example silicones, polydimethylsiloxanes, alkoxysilanes, alkylsilanes and siloxy silicates; organofluorine compounds, for example perfluoroalkyl ethers; fluorosilicone compounds.

The surface-treated pigments that are useful in the cosmetic composition according to the invention may also have been treated with a mixture of these compounds and/or may have undergone several surface treatments.

The surface-treated pigments that are useful in the context of the present invention may be prepared according to surface-treatment techniques that are well known to those skilled in the art, or may be commercially available as is. Preferably, the surface-treated pigments are coated with an organic layer.

The organic agent with which the pigments are treated may be deposited on the pigments by evaporation of solvent, chemical reaction between the molecules of the surface agent or creation of a covalent bond between the surface agent and the pigments. The surface treatment may thus be performed, for example, by chemical reaction of a surface agent with the surface of the pigments and creation of a covalent bond between the surface agent and the pigments or the fillers. This method is notably described in patent US 4 578 266.

An organic agent covalently bonded to the pigments will preferably be used.

The agent for the surface treatment may represent from 0.1% to 50% by weight, preferably from 0.5% to 30% by weight and even more preferentially from 1% to 10% by weight relative to the total weight of the surface-treated pigments.

Preferably, the surface treatments of the pigments are chosen from the following treatments:

- a PEG-silicone treatment, for instance the AQ surface treatment sold by

LCW;

- a chitosan treatment, for instance the CTS surface treatment sold by LCW;

- a triethoxycaprylylsilane treatment, for instance the AS surface treatment sold by LCW;

- a methicone treatment, for instance the SI surface treatment sold by LCW;

- a dimethicone treatment, for instance the Covasil 3.05 surface treatment sold by LCW;

- a dimethicone/trimethyl siloxysilicate treatment, for instance the Covasil 4.05 surface treatment sold by LCW;

- a lauroyllysine treatment, for instance the LL surface treatment sold by LCW; - a lauroyllysine dimethicone treatment, for instance the LL/SI surface treatment sold by LCW;

- a magnesium myristate treatment, for instance the MM surface treatment sold by LCW;

- an aluminium dimyristate treatment, such as the MI surface treatment sold by Miyoshi;

- a perfluoropolymethyl isopropyl ether treatment, for instance the LHC surface treatment sold by LCW;

- an isostearyl sebacate treatment, for instance the HS surface treatment sold by Miyoshi; - a disodium stearoyl glutamate treatment, for instance the NAI surface treatment sold by Miyoshi;

- a dimethicone/disodium stearoyl glutamate treatment, for instance the SA/NAI surface treatment sold by Miyoshi;

- a perfluoroalkyl phosphate treatment, for instance the PF surface treatment sold by Daito;

- an acrylate/dimethicone copolymer and perfluoroalkyl phosphate treatment, for instance the FSA surface treatment sold by Daito;

- a polymethylhydrogenosiloxane/perfluoroalkyl phosphate treatment, for instance the FS01 surface treatment sold by Daito;

- a lauroylly sine/aluminium tristearate treatment, for instance the LL-StAl surface treatment sold by Daito;

- an octyltriethylsilane treatment, for instance the OTS surface treatment sold by Daito;

- an octyltriethylsilane/perfluoroalkyl phosphate treatment, for instance the FOTS surface treatment sold by Daito;

- an acrylate/dimethicone copolymer treatment, for instance the ASC surface treatment sold by Daito;

- an isopropyl titanium triisostearate treatment, for instance the ITT surface treatment sold by Daito;

- a microcrystalline cellulose and carboxymethylcellulose treatment, for instance the AC surface treatment sold by Daito;

- a cellulose treatment, for instance the C2 surface treatment sold by Daito;

- an acrylate copolymer treatment, for instance the APD surface treatment sold by Daito;

- a perfluoroalkyl phosphate/isopropyl titanium triisostearate treatment, for instance the PF + ITT surface treatment sold by Daito.

The composition in accordance with the present invention may furthermore comprise one or more pigments that are not surface-treated.

According to a particular embodiment of the invention, the pigment(s) are mineral pigments.

According to another particular embodiment of the invention, the pigment(s) are chosen from nacres. According to a particular embodiment of the invention, the dispersant is present with organic pigments in the oily dispersion (A) and/or composition (B) and/or composition (C) or with inorganic pigments in particulate form of submicron size.

The term “submicron” or “submicronic” refers to pigments having a particle size that has been micronized by a micronization method and having a mean particle size of less than a micrometre (pm), in particular between 0.1 and 0.9 pm, and preferably between 0.2 and 0.6 pm.

According to one embodiment, the dispersant and the pigment(s) are present in an amount (dispersanhpigment) of between 0.5:1 and 2:1, particularly between 0.75:1 and 1.5:1 or better still between 0.8:1 and 1.2:1.

According to a particular embodiment, the dispersant is suitable for dispersing the pigments and is compatible with a condensation-curable formulation.

The term “compatible” means, for example, that said dispersant is miscible in the oily phase of the composition or of the dispersion containing the pigment(s), and it does not retard or reduce the curing. The dispersant is preferably cationic.

The dispersant(s) may therefore have a silicone backbone, such as silicone polyether and dispersants of amino silicone type. Among the suitable dispersants that may be mentioned are:

- amino silicones, i.e. silicones comprising one or more amino groups such as those sold under the names and references: BYK LPX 21879 by BYK, GP-4, GP-6, GP-344, GP-851, GP-965, GP-967 and GP-988-1, sold by Genesee Polymers,

- silicone acrylates such as Tego® RC 902, Tego® RC 922, Tego® RC 1041, and Tego® RC 1043, sold by Evonik,

- polydimethylsiloxane (PDMS) silicones bearing carboxyl groups such as X- 22162 and X-22370 by Shin-Etsu, epoxy silicones such as GP-29, GP-32, GP-502, GP- 504, GP-514, GP-607, GP-682, and GP-695 by Genesee Polymers, or Tego® RC 1401, Tego® RC 1403, Tego® RC 1412 by Evonik.

According to a particular embodiment, the dispersant(s) are of amino silicone type and are positively charged.

Mention may also be made of dispersants bearing chemical groups that are capable of reacting with the reagents of the oily phase and are thus capable of improving the 3D network formed from the amino silicones. For example, dispersants of epoxy silicone pigments can react chemically with the amino silicone prepolymer amino group(s) to increase the cohesion of the amino silicone film comprising the pigment(s). Preferably, the pigment(s) are chosen from carbon black, iron oxides, notably red and black iron oxides, and micas coated with iron oxide, triarylmethane pigments, notably blue and purple triarylmethane pigments, such as Blue 1 Lake, azo pigments, notably red azo pigments, such as D & C Red 7, alkali metal salt of lithol red, such as the calcium salt of lithol red B.

According to a particular embodiment of the invention, the dyestuff(s) are included in the oily dispersion (A). In other words, according to this embodiment, the oily dispersion (A) comprises:

(1) one or more ethylenic polymer particles as defined previously,

(2) one or more stabilizers, other than said ethylenic polymer(s) a), as defined previously,

(3) one or more hydrocarbon-based oils as defined previously, and

(4) one or more dyestuffs chosen from pigments, direct dyes and mixtures thereof, and preferably from pigments and mixtures thereof.

The total content of the dyestuff(s) used in the colouring process according to the present invention preferably ranges from 0.5% to 20% by weight and more preferentially from 1% to 15% by weight relative to the total weight of the composition comprising same.

The oily dispersion (A) and/or composition (B) and/or optionally composition (C) used in the colouring process according to the invention may also optionally comprise one or more additional compounds other than the compounds defined above, preferably chosen from anionic, cationic, nonionic, amphoteric and zwitterionic surfactants and mixtures thereof, anionic, cationic, nonionic, amphoteric and zwitterionic polymers and mixtures thereof, mineral or organic thickeners, and in particular anionic, cationic, nonionic or amphoteric polymeric associative thickeners, antioxidants, penetrants, sequestrants, fragrances, buffers, dispersants, conditioning agents, for instance volatile or non-volatile, modified or unmodified silicones, film forming agents, ceramides, preserving agents and opacifiers.

Preferably, when the above additional compound(s) are present in the oily dispersion (A) and/or composition (B) and/or optionally composition (C) according to the invention, the additional compound(s) are generally present in an amount, for each of them, of between 0.01% and 20% by weight, relative to the weight of the composition comprising same.

Needless to say, a person skilled in the art will take care to select this or these optional additional compound(s) such that the advantageous properties intrinsically associated with the compositions of the invention are not, or are not substantially, adversely affected by the envisaged addition(s).

Cosmetic treatment process

One subject of the present invention is a cosmetic process for treating keratin materials, in particular human keratin materials such as the hair, the skin or the lips, comprising:

(i) a step of applying to said keratin materials an oily dispersion (A), which is preferably anhydrous, comprising:

(1) one or more particles including one or more ethylenic polymers chosen from: a) (Ci-C ₄ )alkyl (Ci-C ₄ )(alkyl)acrylate ethylenic homopolymers, b) ethylenic copolymers of bl) (Ci-C ₄ )alkyl (Ci-C ₄ )(alkyl)acrylate and of b2) ethylenic monomers comprising one or more carboxyl, anhydride, phosphoric acid, sulfonic acid and/or aryl groups, and c) (Ci-C ₄ )alkyl (Ci-C ₄ )(alkyl)acrylate ethylenic copolymers;

(2) one or more stabilizers, other than said ethylenic polymer(s) (1), chosen from: d) (C ₉ -C ₂₂ )alkyl (Ci-C ₆ )(alkyl)acrylate ethylenic homopolymers, and e) ethylenic copolymers of (C ₉ -C ₂₂ )alkyl (Ci-C ₆ )(alkyl)acrylate and of (Ci-C ₄ )alkyl (Ci-C ₄ )(alkyl)acrylate, and

(3) one or more hydrocarbon-based oils, followed by

(ii) a step of applying to said keratin materials a composition (B) comprising:

(4) one or more amino silicones, and

(5) one or more salified or non-salified polysaccharides bearing amine group(s); it being understood that said process involves (6) one or more dyestuffs chosen from colorants, pigments and mixtures thereof, said dyestuff(s) being present in the oily dispersion (A) and/or in composition (B) and/or in another composition (C).

In other words, the process of the invention is a process in at least two steps, in which composition (B) is applied to the keratin materials after the oily dispersion (A). According to a preferred embodiment, composition (B) is applied directly after composition (A) without an intermediate leave-on time.

According to another particular embodiment, composition (B) is applied to the keratin materials after a leave-on time of between 1 and 60 minutes, and preferably between 1 and 30 minutes.

According to a first embodiment, the cosmetic treatment process according to the invention is a process for making up keratin materials, in particular human keratin materials such as the hair, the skin or the lips.

More particularly, the process of the invention is a process for making up the skin or the lips.

According to another embodiment, the cosmetic treatment process according to the invention is a process for colouring keratin materials, in particular keratin fibres such as the hair.

For the purposes of the present invention, the term "keratin materials" means human keratin materials, such as the hair, the skin or the lips.

The device

A subject of the invention is also a multi-compartment device comprising:

- a first compartment containing an oily dispersion (A) as defined previously,

- a second compartment containing a composition (B) as defined previously, and

- optionally a third compartment containing one or more dyestuffs chosen from pigments, direct dyes and mixtures thereof.

The composition packaging assembly, i.e. the multi-compartment device, is, in a known manner, any packaging that is suitable for storing cosmetic compositions (notably a bottle, tube, spray bottle or aerosol can).

Such a kit allows the cosmetic process for treating keratin materials according to the invention to be performed.

The examples that follow serve to illustrate the invention without, however, being limiting in nature.

Examples

Example 1: The oily dispersions (A) are formed as a whole [particles of ethylenic polymers (1) + stabilizer (2)] containing:

- 70% by weight of ethyl acrylate,

- 10% by weight of maleic anhydride, and - 20% by weight of isobomyl acrylate.

The preparation of these oily dispersions was performed in a 1 litre pilot reactor. The synthesis is performed in two steps:

In a first step, isobornyl acrylate is polymerized in isododecane/ethyl acetate (60/40) in the presence of a small amount of ethyl acrylate and of a radical initiator

Trigonox 21S (T21S). In the first step, the isobornyl acrylate/ethyl acrylate mass ratio is 92/8.

In the second step, the rest of the ethyl acrylate and the maleic anhydride are added in the presence of isododecane/ethyl acetate (60/40) and of the radical initiator Trigonox 2 IS (T21S).

After stripping, the polymer is at a solids content of 52% in the isododecane. The ratios employed to obtain the stabilizer and the particulate core are summarized in Table 1 below:

[Table 1]

The amounts of reagents are given in the tables below: Step 1

[Table 2]

Isododecane added between the two steps: [Table 3] Step 2: [Table 41

Experimental protocol:

Isododecane/ethyl acetate (60/40), isobornyl acrylate, ethyl acrylate and T21S are introduced as feedstock into a reactor. The medium is heated to 90°C under argon and with stirring. The solids content during this first step is 35.9%.

After heating for 2 hours, NMR indicates an isobornyl acrylate consumption of 97% (ethyl acrylate consumption: 97%).

After 2 hours of reaction, isododecane/ethyl acetate (60/40) are introduced into the feedstock. The medium is heated to 90°C.

Once the medium is at 90°C, ethyl acrylate/maleic anhydride, isododecane/ethyl acetate (60/40) and T21S are introduced over 2 hours by pouring. At the end of the introduction by pouring, the medium is milky. The solids content is 40%. After 7 hours of synthesis, traces of the starting monomers remain. 1L of isododecane and of ethyl acetate are then stripped out (NMR indicates that there are no more monomers and that the ethyl acetate has been totally removed from the dispersion). The solids content is about 52%. Example 2

1) Preparation of the compositions

The oily dispersion (A) and compositions (Bl), (B2) and (B3) according to the invention were prepared from the ingredients mentioned in the tables below, the contents of which are expressed as weight percentages relative to the total weight of the composition concerning same.

[Table 5]

⁽¹⁾ sold under the reference Unipure Red LC 3079 OR, by the company Sensient

[Table 61 ( ¹⁾ sold by the company Kitozyme

⁽²⁾ sold by the company Momentive Performance Materials 3 sold by the company Goldschmidt under the reference Abil EM 90 2) Protocol

The oily dispersion (A) thus obtained was applied to a vitro support such as byko-charts (black scrub panels from the company Byk) using a film spreader so as to obtain a deposit with a wet thickness of 50 pm. After drying for 24 hours, compositions (B 1) to (B3) were applied onto the deposit of oily dispersion (A) using a film spreader. The deposits of compositions (Bl) to (B3) have a wet thickness of 50 pm. After application, the compositions were left to dry for 24 hours.

The resistance to water or to olive oil of each of the deposits (A alone), (A+Bl), (A+B2) and (A+B3) was evaluated in the following manner: 0.5 ml of water or of olive oil was deposited on each of the deposits (A alone), (A+Bl), (A+B2) and (A+B3). After a leave-on time of 5 minutes, cotton wool was wiped 15 times over each deposit and the degradation of the deposit was observed. A score ranging from 1 to 5 was then given to each deposit as a function of the degradation of the deposit according to the following scale: 1 corresponds to good resistance of the deposit and little degradation, whereas 5 corresponds to strong degradation (i.e. virtually nothing is left on the support) and thus to poor resistance.

The tacky feel and the transfer of colouring were evaluated by touch. A panel of five experts gave a score ranging from 1 to 5 for each feature according to the following scale: 1 corresponds to a non-tacky feel and no transfer of colouring, whereas 5 corresponds to a very tacky feel and transfer of colouring.

3) Results

The results are collated in the following table (average of five scores). [Table 7]

The above results show that the two-step process of the present invention gives a coating which has improved resistance to water and to olive oil. Moreover, the coating obtained by means of the process of the invention is not tacky and no transfer of colouring is observed.

Example 3

1) Preparation of the compositions

The oily dispersions (Al) and (A2) according to the invention were prepared from the ingredients mentioned in the table below, the contents of which are expressed as weight percentages relative to the total weight of the composition concerning same. Composition (B3) was prepared from the ingredients mentioned in Example

2.

[Table 8]

⁽¹⁾ mixture of dimethiconol resin, liquid dimethicone and dimethicone from Dow Coming

2) Protocol

The oily dispersions (Al) and (A2) thus obtained were applied to a vitro support such as byko-charts (black scrub panels from the company Byk) using a film spreader so as to obtain a deposit with a wet thickness of 50 pm. After drying for 24 hours, composition (B3) was applied to each of the deposits of oily dispersions (Al) or (A2) using a film spreader. The deposit of composition (B3) has a wet thickness of 50 pm. After application, the composition was left to dry for 24 hours.

The resistance to water or to olive oil of each of the deposits (Al alone), (A1+B3), (A2 alone) and (A2+B3) was evaluated in the following manner: 0.5 ml of water or of olive oil was deposited on each of the deposits (Al alone), (A1+B3), (A2 alone) and (A2+B3). After a leave-on time of 5 minutes, cotton wool was wiped 15 times over each deposit and the degradation of the deposit was observed. A score ranging from 1 to 5 was then given to each deposit as a function of the degradation of the deposit according to the following scale: 1 corresponds to good resistance of the deposit and little degradation, whereas 5 corresponds to strong degradation (i.e. virtually nothing is left on the support) and thus to poor resistance.

The tacky feel and the transfer of colouring were evaluated by touch. A panel of five experts gave a score ranging from 1 to 5 for each feature according to the following scale: 1 corresponds to a non-tacky feel and no transfer of colouring, whereas 5 corresponds to a very tacky feel and transfer of colouring.

3) Results

The results are collated in the following table (average of five scores). [Table 9]

The above results show that the two-step process of the present invention gives a coating which has improved resistance to water and to olive oil. Moreover, the coating obtained by means of the process of the invention is not tacky and no transfer of colouring is observed.

Example 4: persistence of the colouring

1) Preparation of the compositions

The oily dispersion (A3) according to the invention was prepared from the ingredients mentioned in the table below, the contents of which are expressed as weight percentages relative to the total weight of the composition concerning same. [Table 10]

⁽¹⁾ sold by Sun under the reference Sunpuro Red Iron Oxide C33-8001

Composition (B3) was prepared from the ingredients mentioned in Example 2. Comparative composition (B4) was prepared from the ingredients mentioned in the table below, the contents of which are expressed as weight percentages relative to the total weight of the composition.

[Table 111

⁽¹⁾ sold by the company Kitozyme

2) Protocol

The process according to the invention (A3+B3) and the comparative process (A3+B4) were performed on locks of natural hair containing 90% grey hairs according to the following protocol: The oily dispersion (A3) thus obtained was applied to the locks of natural hair containing 90% grey hairs, in a proportion of 0.5 g of dispersion per gram of lock. The locks of hair were then combed and dried with a hairdryer.

Compositions (B3) and (B4) were then applied to said locks of hair, in a proportion of 0.5 g of composition per gram of lock. The locks of hair are then combed and then dried with a hairdryer. On conclusion of each of the processes mentioned above, the locks of hair of hair were washed according to the following protocol:

The locks were washed with a Gamier Ultra Doux shampoo. The locks were then rinsed with water, after which they were combed and dried with a hairdryer. This protocol was repeated five times for each of the locks.

The persistence of the colour of the locks is then evaluated by colorimetry in the CIE L*a*b* system, using a Minolta CM 3600D spectrocolorimeter (illuminant D65, angle 10°, specular component included). In this L*a*b* system, L* represents the lightness of the colour, a* indicates the green/red colour axis and b* the blue/yellow colour axis. The smaller the value of L*, the darker and more powerful the colouring. The smaller the value of a*, the greener the colour and the higher the value of a*, the redder the colour. The smaller the value of b*, the bluer the colour and the higher the value of b*, the yellower the colour.

The persistence of the colouring is evaluated by the colour difference DE* between the dyed locks before shampoo washing and the dyed locks which have been shampoo washed five times. DE* is defined according to the following equation: In this equation, L*, a* and b* represent the values measured after dyeing the hair and after performing five shampoo washes, and Lo*, ao* and bo* represent the values measured after dyeing the hair but without shampoo washing.

The lower the value of DE*, the greater the resistance of the colourings with respect to shampoo washing.

3) Results

The colorimetric values obtained after dyeing the locks (before and after shampoo washing) by means of the processes mentioned above are given in the table below. [Table 121

The results obtained above show that the colour of the locks treated by means of the process according to the present invention, i.e. comprising the application of at least two amine compounds that are different from each other (A3+B3), shows better persistence with respect to shampoo washing than the locks treated by means of the comparative process (A3+B4). Specifically, the colour persists even after five shampoo washes.